From a050d6063c78004de8b4b5945cb03bb43d84c8de Mon Sep 17 00:00:00 2001 From: Campbell Barton Date: Wed, 13 May 2015 18:04:46 +1000 Subject: Project Paint: resolve ugly bleed artifacts Use the bilinear reverse to find the pixel to bleed from. Was using pixel space which didn't work well. --- source/blender/blenlib/BLI_math_geom.h | 1 + source/blender/blenlib/intern/math_geom.c | 37 ++++++++++++++++++++++ .../editors/sculpt_paint/paint_image_proj.c | 7 ++-- 3 files changed, 40 insertions(+), 5 deletions(-) (limited to 'source/blender') diff --git a/source/blender/blenlib/BLI_math_geom.h b/source/blender/blenlib/BLI_math_geom.h index 4f7a3310ee6..4a75e83316e 100644 --- a/source/blender/blenlib/BLI_math_geom.h +++ b/source/blender/blenlib/BLI_math_geom.h @@ -259,6 +259,7 @@ void resolve_tri_uv_v3(float r_uv[2], const float st[3], const float st0[3], con void resolve_quad_uv_v2(float r_uv[2], const float st[2], const float st0[2], const float st1[2], const float st2[2], const float st3[2]); void resolve_quad_uv_v2_deriv(float r_uv[2], float r_deriv[2][2], const float st[2], const float st0[2], const float st1[2], const float st2[2], const float st3[2]); +float resolve_quad_u_v2(const float st[2], const float st0[2], const float st1[2], const float st2[2], const float st3[2]); /* use to find the point of a UV on a face */ void interp_bilinear_quad_v3(float data[4][3], float u, float v, float res[3]); diff --git a/source/blender/blenlib/intern/math_geom.c b/source/blender/blenlib/intern/math_geom.c index ba1f4480659..82062e80ae8 100644 --- a/source/blender/blenlib/intern/math_geom.c +++ b/source/blender/blenlib/intern/math_geom.c @@ -3101,6 +3101,43 @@ void resolve_quad_uv_v2_deriv(float r_uv[2], float r_deriv[2][2], } } +/* a version of resolve_quad_uv_v2 that only calculates the 'u' */ +float resolve_quad_u_v2( + const float st[2], + const float st0[2], const float st1[2], const float st2[2], const float st3[2]) +{ + const double signed_area = (st0[0] * st1[1] - st0[1] * st1[0]) + (st1[0] * st2[1] - st1[1] * st2[0]) + + (st2[0] * st3[1] - st2[1] * st3[0]) + (st3[0] * st0[1] - st3[1] * st0[0]); + + /* X is 2D cross product (determinant) + * A = (p0 - p) X (p0 - p3)*/ + const double a = (st0[0] - st[0]) * (st0[1] - st3[1]) - (st0[1] - st[1]) * (st0[0] - st3[0]); + + /* B = ( (p0 - p) X (p1 - p2) + (p1 - p) X (p0 - p3) ) / 2 */ + const double b = 0.5 * (double)(((st0[0] - st[0]) * (st1[1] - st2[1]) - (st0[1] - st[1]) * (st1[0] - st2[0])) + + ((st1[0] - st[0]) * (st0[1] - st3[1]) - (st1[1] - st[1]) * (st0[0] - st3[0]))); + + /* C = (p1-p) X (p1-p2) */ + const double fC = (st1[0] - st[0]) * (st1[1] - st2[1]) - (st1[1] - st[1]) * (st1[0] - st2[0]); + double denom = a - 2 * b + fC; + + if (IS_ZERO(denom) != 0) { + const double fDen = a - fC; + if (IS_ZERO(fDen) == 0) + return (float)(a / fDen); + else + return 0.0f; + } + else { + const double desc_sq = b * b - a * fC; + const double desc = sqrt(desc_sq < 0.0 ? 0.0 : desc_sq); + const double s = signed_area > 0 ? (-1.0) : 1.0; + + return (float)(((a - b) + s * desc) / denom); + } +} + + #undef IS_ZERO /* reverse of the functions above */ diff --git a/source/blender/editors/sculpt_paint/paint_image_proj.c b/source/blender/editors/sculpt_paint/paint_image_proj.c index 400202ab61a..8bf4395add2 100644 --- a/source/blender/editors/sculpt_paint/paint_image_proj.c +++ b/source/blender/editors/sculpt_paint/paint_image_proj.c @@ -2825,11 +2825,8 @@ static void project_paint_face_init( /* Since this is a seam we need to work out where on the line this pixel is */ //fac = line_point_factor_v2(uv, uv_seam_quad[0], uv_seam_quad[1]); - - fac = line_point_factor_v2(uv, seam_subsection[0], seam_subsection[1]); - if (fac < 0.0f) { copy_v3_v3(pixelScreenCo, edge_verts_inset_clip[0]); } - else if (fac > 1.0f) { copy_v3_v3(pixelScreenCo, edge_verts_inset_clip[1]); } - else { interp_v3_v3v3(pixelScreenCo, edge_verts_inset_clip[0], edge_verts_inset_clip[1], fac); } + fac = resolve_quad_u_v2(uv, UNPACK4(seam_subsection)); + interp_v3_v3v3(pixelScreenCo, edge_verts_inset_clip[0], edge_verts_inset_clip[1], fac); if (!is_ortho) { pixelScreenCo[3] = 1.0f; -- cgit v1.2.3